Lack of progress in student writing achievement has been linked to the variability in teachers' instructional practice. This mixed-methods study examines the links between university coursework in writing instruction and the dispositions, skills, and knowledge of twelve practicing teachers, grades 1-6; six of which participated in the course and six who did not. Data from response-guided interviews, daily logs, structured classroom observations, and follow-up interviews have been analyzed, compared, and integrated. Analyses found significant differences between groups for instruction in the writing processes, self-regulation skills, use of social interaction, and writing in multiple genres across the curriculum. Further analysis found differences in teacher's perceptions of their preparation to teach writing and shared perceptions of their state and district's provision of accountability and resources. Findings suggest implications for teacher professional development, literacy teacher educators, and teacher education researchers.